Seed overview API endpoint

[pkprzekwas]

What this PR does / why we need it:
Admin seed details view.

Which issue(s) this PR fixes:

Fixes #9834

What type of PR is this?
/kind feature

Does this PR introduce a user-facing change? Then add your Release Note here:

New admin api endpoint for fetching seed's details.

Documentation:

https://docs.kubermatic.com/kubermatic/main/tutorials-howtos/administration/admin-panel/seed-configurations/

[codecov]

Codecov Report

Merging #5213 (6c9b942) into main (6d399d3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #5213   +/-   ##
=======================================
  Coverage   48.18%   48.18%           
=======================================
  Files         398      398           
  Lines       15390    15390           
  Branches     2748     2748           
=======================================
  Hits         7416     7416           
  Misses       7516     7516           
  Partials      458      458           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6d399d3...6c9b942. Read the comment docs.

[ahmedwaleedmalik]

/approve
/retest

[kubermatic-bot]

LGTM label has been added.

Git tree hash: ad20cc789a810f8ca781483589b5256fb34a551e

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahmedwaleedmalik, pkprzekwas

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [ahmedwaleedmalik,pkprzekwas]
• cmd/kubermatic-api/OWNERS [ahmedwaleedmalik,pkprzekwas]
• pkg/api/OWNERS [ahmedwaleedmalik,pkprzekwas]
• pkg/handler/OWNERS [ahmedwaleedmalik,pkprzekwas]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment